Mount Semeru Erupts Again This Morning, Volcanic Ash Plume 800 Meters Above Peak

Mount Semeru in East Java erupted again on Saturday (17/1/2026) at 05.38 WIB. In the last week, Mount Semeru has erupted 40 times.

Citing eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the ash column was observed to be about 800 meters above the peak (4,476 meters above sea level).

The ash column was observed to be white to gray with moderate intensity towards the northeast. The eruption of Mount Semeru was still ongoing when this report was made.

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According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on January 17, 2026, from 18.00-23.59 WIB showed 28 eruption tremors/earthquakes with amplitudes of 10-22 millimeters and durations of 83-147 seconds.

Additionally, there were 8 exhalation tremors with amplitudes of 3-6 millimeters and durations of 45-58 seconds, and 5 harmonic tremors with amplitudes of 2-15 millimeters and durations of 135-427 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond this distance, people should not engage in activities within 500 meters from the riverbanks (river borders) along Besuk Kobokan, as there is a potential for expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 229 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 129 occurrences.

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